File Coverage

lib/lvalue.pm

Criterion	Covered	Total	%
statement	53	53	100.0
branch	15	18	83.3
condition	2	3	66.6
subroutine	15	15	100.0
pod	2	2	100.0
total	87	91	95.6

package lvalue;

use warnings;
use strict;
#use ex::provide [qw(get set)];
use Carp;

sub import {
	my $pkg = shift;
	my $pk = caller;
	no strict 'refs';
	for (@_ ? @_ : qw(get set)) {
		defined &$_ or croak "$_ is not exported by $pk";
		*{ $pk . '::' . $_ } = \&$_;
	}
}
=head1 NAME

lvalue - use lvalue subroutines with ease

=head1 VERSION

Version 0.01

=cut

our $VERSION = '0.01';


=head1 SYNOPSIS

Simply put get and set blocks at the end of your lvalue sub.
Please note, no comma or semicolon between statements are allowed (in case of semicolon only last statement will be take an action)

	use lvalue;

	sub mysub : lvalue {
		get {
			return 'result for get';
		}
		set {
			my $set_value = shift;
			# ...
		}
	}

	mysub() = 'test'; # will invoke set block with argument 'test';
	print mysub(); # will invoke get block without arguments. result will be returned to print;

	sub readonly : lvalue {
		get {
			return 'readonly value';
		}
	}

	print readonly();  # ok
	readonly = 'test'; # fails

	sub writeonly : lvalue {
		set {
			my $set_value = shift;
			# ...
		}
	}

	writeonly = 'test'; # ok
	print writeonly();  # fails

=head1 EXPORT

There are 2 export functions: C and C. If you don't want to use export, you may use full names

	sub mysub : lvalue {
		lvalue::get {
			return 'something';
		}
		lvalue::set {
			my $set_value = shift;
		}
	}

=head1 FUNCTIONS

=head2 set

invoked with argument from right side

=cut

sub set (&;@) : lvalue {
	my $code = shift;
	if (@_) {
		tied($_[0])->set($code);
	}else{
		tie $_[0], 'lvalue::tiecallback', undef, $code;
	}
	$_[0];
}

=head2 get

invoked without arguments. the returned value passed out

=cut

sub get (&;@) : lvalue {
	my $code = shift;
	if (@_) {
		tied($_[0])->get($code);
	}else{
		tie $_[0], 'lvalue::tiecallback', $code, undef;
	}
	$_[0];
}

=head1 AUTHOR

Mons Anderson,

=head1 BUGS

None known

=head1 COPYRIGHT & LICENSE

Copyright 2009 Mons Anderson.

This program is free software; you can redistribute it and/or modify it
under the same terms as Perl itself.

=cut

package lvalue::tiecallback;

use strict;
use Sub::Name;
use Carp;
our @CARP_NOT = 'lvalue';

sub set {
	$_[0]->[1] = $_[1];
}
sub get {
	$_[0]->[0] = $_[1];
}

sub TIESCALAR {
	my ($pkg,$get,$set) = @_;
	my $caller = (caller(2))[3];
	subname $caller.':get',$get if $get;
	subname $caller.':set',$set if $set;
	$get or $set or croak "Neither set nor get passed";
	return bless [$get,$set,$caller],$pkg;
}
sub FETCH {
	my $self = shift;
	defined $self->[0] or croak "$self->[2] is writeonly";
	goto &{ $self->[0] };
}
sub STORE {
	my $self = shift;
	defined $self->[1] or croak "$self->[2] is readonly";
	goto &{ $self->[1] };
}

1;